Antenna Grid Research Articles

Passive radio frequency identification and video tracking for the determination of location and movement of broilers

Phenotypes on individual animals are required for breeding programs to be able to select for traits. However, phenotyping individual animals can be difficult and time-consuming, especially for traits related to health, welfare, and performance. Individual broiler behavior could serve as a proxy for these traits when recorded automatically and reliably on many animals. Sensors could record individual broiler behavior, yet different sensors can differ in their assessment. In this study a comparison was made between a passive radio frequency identification (RFID) system (grid of antennas underneath the pen) and video tracking for the determination of location and movement of 3 color-marked broilers at d 18. Furthermore, a systems comparison of derived behavioral metrics such as space usage, locomotion activity and apparent feeding and drinking behavior was made. Color-marked broilers simplified the computer vision task for YOLOv5 to detect, track, and identify the animals. Animal locations derived from the RFID-system and based on video were largely in agreement. Most location differences (77.5%) were within the mean radius of the antennas' enclosing circle (≤128 px, 28.15 cm), and 95.3% of the differences were within a one antenna difference (≤256 px, 56.30 cm). Animal movement was not always registered by the RFID-system whereas video was sensitive to detection noise and the animal's behavior (e.g., pecking). The method used to determine location and the systems' sensitivities to movement led to differences in behavioral metrics. Behavioral metrics derived from video are likely more accurate than RFID-system derived behavioral metrics. However, at present, only the RFID-system can provide individual identification for non-color marked broilers. A combination of verifiable and detailed video with the unique identification of RFID could make it possible to identify, describe, and quantify a wide range of individual broiler behaviors.

Effects of Crystallographic Orientation of GaAs Substrate and the Period of Plasmon Grid on THz Antenna Performance

AbstractAn alternative approach is proposed to improve the conventional (based on the low‐temperature grown GaAs and Si‐doped GaAs superlattice) photoconductive antenna (PCA) performance by modification of the planar electrodes design and crystallographic orientations of the GaAs substrate ((100) and (111)‐A). The electrode scheme design includes a combination of logarithmic spiral, bow‐tie, and plasmonic antennas and results in appearance of sharp resonant peaks, high spectral bandwidth and high signal‐to‐noise ratio, and significant enhancement of the output terahertz (THz) power. The material design leads to significant increase in the THz output power (by 6.4 in GaAs (100), by 5.6 in GaAs (111)‐A PCAs) regarding to a conventional antenna. The substrate crystallographic cut direction influences the relaxation time constant of photoexcited charge carriers being an order of magnitude smaller in the sample grown on the GaAs (111)‐A than in the one on the GaAs (100). The simulation model supports experimental results demonstrating that the optimal period of the plasmonic antenna grid providing the highest efficiency of THz radiation generation, is about 200 nm. Comparison of the THz spectra in manufactured antennas against the conventional stripline PCA shows a broadening band toward the low‐frequency region down to 0.1 THz with a resonance at 0.2 THz.

Researching Digital Methods of Generation Signals of Hydroacoustic Phased Antenna Grids

Solving tasks of creation, correction and parametric control of signals excitation hydroacoustic phased antenna grids is actual problem of creating multichannel generated devices, based on switch-mode amplifiers with pulse-width modulation. In this article were reviewed correction methods output signals of hydroacoustic transmission paths, periodic pulse sequence creation and parametric voltage level control of excitation channels of phased antenna grid with abrupt decrease impedance of hydroacoustic converters. Was shown the perspective implementation digital technologies for improvement parameters modes of hydrolocation with deterministic library of signals. Presented digital control methods of output signals in hydroacoustic transmission paths are characterized by scientific novelty and originality of the proposed technical decisions.

Arena: A 64-antenna SDR-based ceiling grid testing platform for sub-6 GHz 5G-and-Beyond radio spectrum research

Arena is an open-access wireless testing platform based on a grid of antennas mounted on the ceiling of a large office-space environment. Each antenna is connected to programmable software-defined radios (SDR) enabling sub-6 GHz 5G-and-beyond spectrum research. With 12 computational servers, 24 SDRs synchronized at the symbol level, and a total of 64 antennas, Arena provides the computational power and the scale to foster new technology development in some of the most crowded spectrum bands. Arena is based on a three-tier design, where the servers and the SDRs are housed in a double rack in a dedicated room, while the antennas are hung off the ceiling of a 2240 square feet office space and cabled to the radios through 100 ft-long cables. This ensures a reconfigurable, scalable, and repeatable real-time experimental evaluation in a real wireless indoor environment.In this paper, we introduce the architecture, capabilities, and system design choices of Arena, and provides details of the software and hardware implementation of various testbed components. Furthermore, we describe key capabilities by providing examples of published work that employed Arena for applications as diverse as synchronized MIMO transmission schemes, multi-hop ad hoc networking, multi-cell 5G networks, AI-powered Radio-Frequency fingerprinting, secure wireless communications, and spectrum sensing for cognitive radio.

Assessing the Activity of Individual Group-Housed Broilers Throughout Life using a Passive Radio Frequency Identification System-A Validation Study.

Individual data are valuable for assessing the health, welfare and performance of broilers. In particular, data on the first few days of life are needed to study the predictive value of traits recorded early in life for later life performance. However, broilers are generally kept in groups, which hampers individual identification and monitoring of animals. Sensor technologies may aid in identifying and monitoring individual animals. In this study, a passive radio frequency identification (RFID) system was implemented to record broiler activity, in combination with traditional video recordings. The two main objectives were (1) to validate the output of the RFID system by comparing it to the recorded locations on video, and (2) to assess whether the number of antennas visited per unit time could serve as a measure of activity, by comparing it to the distance recorded on video and to the distance moved as recorded using a validated ultra-wideband (UWB) tracking system. The locations recorded by the RFID system exactly matched the video in 62.5% of the cases, and in 99.2% of the cases when allowing for a deviation of one antenna grid cell. There were moderately strong Spearman rank correlations between the distance recorded with the RFID system and the distance recorded from video (rs = 0.82) and between UWB and RFID (rs = 0.70) in approximately one-hour recordings, indicating that the RFID system can adequately track relative individual broiler activity, i.e., the activity level of a broiler in comparison to its group members. As the RFID tags are small and lightweight, the RFID system is well suited for monitoring the individual activity of group-housed broilers throughout life.

Power Reduction Estimation of 5G Active Antenna Systems for Human Exposure Assessment in Realistic Scenarios

Maximum power extrapolation techniques from measured data are usually employed to assess the compliance with standards of average fields radiated by base stations. However, such techniques provide an upper bound, which is not reached in real scenarios. This is particularly true in 5G Communications, where Active Antenna Systems allow a decrease of the average power density according to the adopted scheduling strategy. This paper is focused on the power reduction estimation in realistic scenarios. In particular a deterministic model of a communication system is used to obtain simple formulas only requiring the knowledge of the served area angular extension and of the Envelope Radiation Pattern of the antenna. The model, developed for beam steering and grid of beams antennas, is also extended to analyze the case of Multi User massive Multiple Input Multiple Output (MU-mMIMO) antennas with single layer per user, showing that under proper hypothesis on the beams of the antenna it is possible to estimate the reduction parameter without the explicit knowledge of the number of layers of MU-mMIMO systems. In spite of the simplicity of the approach, comparison with stochastic models and results reported in recent literature show that the formulas obtained using the model proposed in this paper allow to obtain a useful approximation of the power reduction factor, making the formulas suitable for a preliminary fast estimation of the Electromagnetic Field in 5G cells for human exposure assessment.

Development of an Antenna Grid of a Centimetric Range in the MIMO System for Determining Coordinates of Objects

In this work, a block diagram of a system to determine the location of a moving object or objects, which is using the technology of the MIMO (Multiple Input Multiple Output), is proposed. For this system, a microstrip antenna array was modeled and manufactured as an emitter. The numerical modeling of the lattice was carried out using the CADFEKO software package. Based on the obtained simulation results, the operative embodiment was made of the antenna array.

An analytic description of the radio emission of air showers based on its emission mechanisms

The spatial signal distribution of the radio frequency radiation from extensive air showers on the ground contains information on crucial cosmic-ray properties, such as energy and mass. A long-standing challenge to access this information experimentally with a sparse grid of antennas is an analytic modeling of the radio signal distribution, which will be addressed in this contribution. We present an analytic model based on the two physical processes generating radio emission in air showers: the geomagnetic and the charge-excess emission. Our study is based on full Monte-Carlo simulations with the CoREAS code. Besides an improved theoretical understanding of radio emission, our model describes the radio signal distribution with unprecedented precision. Our model explicitly includes polarization information, which basically doubles the information that is used from a single radio station. The model depends only on the definition of the shower axis and on the parameters energy and distance to the emission region, where the distance to the emission region has a direct relation to the cosmic-ray mass. The model describes the true signal distribution precisely such that the model uncertainties are negligible compared to typical experimental uncertainties.

An analytic description of the radio emission of air showers based on its emission mechanisms

Ultra-high energy cosmic rays can be measured through the detection of radio-frequency radiation from air showers. The radio-frequency emission originates from deflections of the air-shower particles in the geomagnetic field and from a time-varying negative charge excess in the shower front. The distribution of the radio signal on the ground contains information on crucial cosmic-ray properties, such as energy and mass. A long standing challenge is to access this information experimentally with a sparse grid of antennas. We present a new analytic model of the radio signal distribution that depends only on the definition of the shower axis and on the parameters energy and distance to the emission region. The distance to the emission region has a direct relation to the cosmic rays mass. This new analytic model describes the different polarizations of the radiation and therefore allows the use of independently measured signals in different polarization, thereby doubling the amount of information that is available in current radio arrays, compared to what has been used thus far. We show with the use of CoREAS Monte Carlo simulation that fitting the measurements with our model does not result in significant contributions in both systematic bias and in resolution for the extracted parameters energy and distance to emission region, when compared to the expected experimental measurement uncertainties. This parametrization also enables fast simulation of radio signal patterns for cosmic rays, without the need to simulate the air shower.

RF Modules (Tx–Rx) with Multifunctional MMICs

Abstract Next generation RF sensor modules for multifunction active electronically steered antenna (AESA) systems will need a combination of different operating modes, such as radar, electronic warfare (EW) functionalities and communications/datalinks within the same antenna frontend. They typically operate in C-Band, X-Band and Ku-Band and imply a bandwidth requirement of more than 10 GHz. For the realisation of modern active electronically steered antennas, the transmit/receive (T/R) modules have to match strict geometry demands. A major challenge for these future multifunction RF sensor modules is dictated by the half-wavelength antenna grid spacing, that limits the physical channel width to < 12 mm or even less, depending on the highest frequency of operation with accordant beam pointing requirements. A promising solution to overcome these geometry demands is the reduction of the total monolithic microwave integrated circuit (MMIC) chip area, achieved by integrating individual RF functionalities, which are commonly achieved through individual integrated circuits (ICs), into new multifunctional (MFC) MMICs. Various concepts, some of them already implemented, towards next generation RF sensor modules will be discussed and explained in this work.

RSSI-based Indoor Localization Using RSSI-with-Angle-based Localization Estimation Algorithm

For the scenarios of indoors localization and tracking, the solutions generally need complex infrastructure because they would require either a grid of antennas, each having a well-known position (proximity based approach), or a sophisticated algorithm that uses scene fingerprint to estimate the location or the zone of an object by matching the online measurement with the closest offline measurement. Those techniques may not be available in unknown zones, which will make it difficult to locate a lost node. In this paper, with no additional hardware costs, we propose a new RSSIbased approach in order to find a lost node using a known node. By rotating the known node at the same spot we can collect different RSSI for different polar angles. Two pairs of angles with the strongest RSSI will indicate the main lobes of the radiation pattern, namely, zone of the unknown node. Experimental results illustrate a very close estimation of the unknown node zone, reducing up to 84% of the zone uncertainty.

PENGUATAN SINYAL GLOBAL SYSTEM FOR MOBILE COMMUNICATION (GSM) 900 MHz MENGGUNAKAN ANTENA GRID

The antenna is a device used to transmit or receive electromagnetic waves electromagnetic waves. Reception using an antenna will amplify the signal acquisition in accordance with the ability of the antenna itself. Service providers GSM (Global System Mobile), with the inclusion of the network limitations make the need for strengthening the acquisition of the signal is very large. Grid antenna is one option reinforcement signal acquisition. Grid antenna has a major component that is driven in the form of a dipole and a reflector which serves to reflect the signal beam. In this final project is designed, realized and measured at the antenna grid on GSM 900 MHz. This antenna is intended to be a media aids in strengthening the GSM signal reception to maximize the signal acquisition and connections

On the possibility of using the maximum entropy method in ultrasonic nondestructive testing for scatterer visualization from a set of echo signals

We have studied the possibility of solving the inverse scattering problem in the Born approximation, i.e., the reconstruction of scatterer images from the measured set of echo signals. We have considered generalization of the classical combined SAFT (C-SAFT) algorithm to the case of multiple reflections from uneven boundaries of the tested object taking into account the transformation of the wave type for several positions of the antenna grid, which makes it possible to obtain high-quality scatterer images. Representation of the direct problem in matrix form makes it possible to switch to solving the inverse problem, which can be solved using the Tikhonov regularization procedure, because it is an ill-posed. We have considered the possibility of using the entropy of the image estimate as the stabilizing functional that forms the essence of the maximum entropy method (MEM). The advantage of the MEM over the conventionally used linear C-SAFT method has been shown. The ray model taking into account reflections of rays from the boundaries of the tested object with uneven boundaries has been used for constructing the function estimate. We have demonstrated the ability of the MEM to obtain the scatterer images with superresolution and to suppress the “side lobes” of the function of the point scattering on the collapsed set of echo signals. The use of echo signals reflected from the boundaries of the tested object makes it possible to reconstruct the scatterer shape more exactly. Examples of images reconstructed by the MEM on echo signals obtained in the numerical and model experiments have been presented.

Development of a flatbed passive integrated transponder antenna grid for continuous monitoring of fishes in natural streams

This paper describes a flatbed antenna grid designed for continuous remote monitoring of fish tagged with 23 mm passive integrated transponder (PIT) tags in a natural stream with extensive spatial coverage. A range of applications of the system is presented.

The production of highly unidirectional lower-hybrid waves

The development of a highly unidirectional lower-hybrid wave source would improve the electron current drive efficiency in tokamaks. Lower-hybrid waves launched from a phased wave array are shown to be reflected from a grid placed in a cold, low-density plasma. The antenna–grid combination results in highly unidirectional lower-hybrid waves.

Optical Tracking and Telemetry for Nocturnal Field Studies

A miniaturized optical telemetry transmitter for small animals was designed, constructed, and field-tested on free-ranging nocturnal crabs. The device produces accurately timed flashes that can be used for individual tagging, tracking, and telemetry. When observed with a night vision scope, the flashes are visible for several hundred meters. Transmitters are inexpensive, relative simple, and rugged. Weight is less than 1 g, and working life is about 4 weeks with 4 g of hearing aid batteries. J. WILDL. MANAGE. 41(2):309-312 Little information exists concerning the behavior and ecology of nocturnal animals, due to the difficulty of observing unrestrained subjects in the dark. The optical device described here was developed to overcome some of the limitations of radiotelemetry for a study of ghost crabs (Ocypode quadrata). Radiotelemetry has been used successfully for long-range tracking (Cochran and Lord 1963), activity monitoring (Knowlton et al. 1968, Osgood and Weigl 1972) and tracing movements of mice (Rawson and Hartline 1964) and voles (Chute et al. 1974). However, the fixes provided by radio, even of animals held in an enclosure under an antenna grid (Chute et al. 1974) are approximate due to the 2-6 m wavelengths used. It is virtually impossible to localize precisely free-ranging animals by radiotriangulation without disturbing them, due to the necessity of taking bearings from several positions at close range. Exact localization and direct observation of nocturnal behavior require seeing in the dark. The image intensifiers (starlight scopes) developed recently make this possible even in faint moonlight. Unfortunately most nocturnal animals are cryptically colored. Starlight scopes cannot create image contras where there is no target contrast; in fact, starlight scopes lose existing chromatic contrast by producing a monochromatic image. I found that ghost crabs, which are hard to see on their natural background by daylight, were impossible to see at night unless moving, even with a good-quality s arlig t cope (Noctron IV, Varo, Inc.). The circuit described here overcomes this difficulty by producing a timed flashing light, visible to the unaided eye at close ranges, and capable of extending the useful range of a starlight scope to distances at which the subject animal would be total y undetectable. In actual use it survived exposure to surf and sand, and permit ed individual recognition and tracking of crabs from distances of up to 300 m in the field, for periods of several weeks. The circuit is quite flexible, and may be modified to telemeter I channel of data.